diff --git a/uppsrc/Core/Stream.h b/uppsrc/Core/Stream.h
index 3c8bb189f..11b31d2cc 100644
--- a/uppsrc/Core/Stream.h
+++ b/uppsrc/Core/Stream.h
@@ -82,6 +82,9 @@ public:
 	int       Term()                 { return ptr < rdlim ? *ptr : _Term(); }
 	int       Get()                  { return ptr < rdlim ? *ptr++ : _Get(); }
 
+	const byte *Peek(int size = 1)   { ASSERT(size > 0); return ptr + size <= rdlim ? ptr : NULL; }
+	byte       *PutPtr(int size = 1) { ASSERT(size > 0); if(ptr + size <= wrlim) { byte *p = ptr; ptr += size; return p; }; return NULL; }
+
 	void      Put(const void *data, dword size)  { if(ptr + size <= wrlim) { memcpy(ptr, data, size); ptr += size; } else _Put(data, size); }
 	dword     Get(void *data, dword size)        { if(ptr + size <= rdlim) { memcpy(data, ptr, size); ptr += size; return size; } return _Get(data, size); }
 
diff --git a/uppsrc/Core/src.tpp/Stream$en-us.tpp b/uppsrc/Core/src.tpp/Stream$en-us.tpp
index d36aede4e..36f94a145 100644
--- a/uppsrc/Core/src.tpp/Stream$en-us.tpp
+++ b/uppsrc/Core/src.tpp/Stream$en-us.tpp
@@ -377,6 +377,22 @@ negative value is returned.&]
 [s7; [*/ Return value]-|Byte read from input stream.&]
 [s3; &]
 [s4;%- &]
+[s5;:Stream`:`:Peek`(int`):%- [@(0.0.255) const]_[_^byte^ byte]_`*[* Peek]([@(0.0.255) int]_[*@3 s
+ize]_`=_[@3 1])&]
+[s2; This is a special optimization method; it might return a pointer 
+to data of [%-*@3 size] bytes at current position in the stream, 
+but it is allowed to return NULL `- in that case you need to 
+load data into buffer using Get.&]
+[s3; &]
+[s4;%- &]
+[s5;:Stream`:`:PutPtr`(int`):%- [_^byte^ byte]_`*[* PutPtr]([@(0.0.255) int]_[*@3 size]_`=_[@3 1
+])&]
+[s2; This is a special optimization method; it might return a writable 
+pointer where you can write output data of [%-*@3 size] bytes, 
+but it is allowed to return NULL `- in that case you need to 
+output data using Put. Advances stream by [%-*@3 size].&]
+[s3; &]
+[s4;%- &]
 [s5;:Stream`:`:Put`(const void`*`,dword`):%- [@(0.0.255) void]_[* Put]([@(0.0.255) const]_[@(0.0.255) v
 oid]_`*[*@3 data], [_^dword^ dword]_[*@3 size])&]
 [s2; Writes a block of raw binary data to the output stream.&]